The embodiments of the present disclosure relate to a lighting device.
At present the application of a pyroelectric sensor in a light fixture is primarily for determining whether a human body enters into a detecting zone and then automatically controlling the switch of the light fixture; however, the sensor for such application produces response only based on the motion of the human body (heat source) and have no response to human body (heat source) in a standstill state in the detecting zone. Even an array composed of a plurality of pyroelectric sensors can not determine whether the heat source is in a standstill state. The ultrasonic sensor techniques are mainly used for distance measuring and vehicle astern running application, capable of determining an object distance based on reflected signals, but has no selectivity for a reflecting body, leading to many incorrect operations when used directly for light fixtures and having no direction determination.
In light emitting diode (LED) illumination (or lighting) and dimming techniques, the existent LED illumination dimming needs an input equipment, such as a key-board, touching pad, remote controller or wireless computer operation etc., affecting appearance rating or cost.
Therefore, existing light fixtures are unable to perfectly control looming by sensing physical displacement, especially a human body at a standstill state in the detecting zone, thus automatic control of light fixtures can not be achieved.